Generally speaking, i think there are way too many 'detect invis' preps in the game. By mid-ranks being able to be invisible is nearly useless except in the rare situation where someone forgot to do whatever they do, or have to detect.

This is contrary to every fantasy story I have ever read where being able to go invisible was a major thing spell-wise.

Either that or perhaps make 'invisibility' get stronger as a person gets up in rank so that stronger preps are required to see someone invisible..

Don't know how this would be coded but I look at it like the prep gives you the ability to 'check' to see if anyone invisible is around you and if say you quaff a level 15 prep you aren't likely to see a level 30 mage who is invisible but if you use a level 30 prep you are guarenteed to see a level 15 mage.